1. Field of the Invention
This invention relates broadly to contact lens packaging and storage container technology. More specifically, this invention relates to "blister" or injection-molded plastic packages for storing hydrophilic or soft contact lenses immersed in a sterile saline storage solution.
2. Description of the Related Art
Hydrophilic or soft contact lenses have become quite popular because of comfort and convenience. These hydrophilic lenses generally contain from about 20% to 90% water by weight. In order to maintain this high water content, hydrophilic lenses are typically immersed in a sterile, aqueous solution within a watertight package during storing, shipping, and handling processes. There have been a variety of packages used to store hydrophilic contact lenses.
Early lens containers were stoppered glass bottles. These bottles were commonly sealed with silicone stoppers and metal foil overcaps for safety. Each bottle, having a volume of about 10 cc, carried a single contact lens immersed in about 7 cc sterile saline solution. The lens was removed by tearing the metal foil, unplugging the stopper, and grasping the lens with tweezers.
Improvements in contact lens packaging include the injection-molded or "blister" package, an example of which is disclosed in U.S. Pat. No. 4,691,820, issued to Martinez. Martinez discloses a contact lens storage package including a blister portion which defines a cavity for receiving a contact lens and saline solution. The blister portion includes an outward extending flange around the perimeter of the cavity. A cover material is affixed to the flange in order to form a watertight seal. A portion of the side wall of the blister portion is inclined away from the bottom resting surface of the blister portion. The package is opened by stripping away the cover from the flange to expose the cavity containing the contact lens. Although the Martinez package provides certain improvements, neither the package nor the cover portion are easily grasped for the opening process.
Thus, there is a need for a hydrophilic contact lens storage package having improved means for grasping the package. Also, there is a need for a contact lens storage package having an improved means for grasping and removing the cover.